In a flat display device, a Thin Film Transistor Liquid Crystal Display (TFT-LCD) has features of small volume, low power consumption, relatively lower manufacturing cost, no radiation and other features, and occupies a leading status in current flat panel display markets. The TFT-LCD is formed by involution of an array substrate and a color filter substrate, wherein the array substrate is mainly manufactured by a 5 mask or 4 mask technology currently. In each photomask manufacturing technology, several steps of washing, drying, film formation, photoetching. shall be gone through. Because there are many procedures in yield, high cost and other problems inevitably exist.